Lifting tool



ril 6, 1 4 K. B. JAMISON 2,674,485

LIFTING TOOL Filed Oct. 30. 1950 606 PIKE/V) 4770,2445) Patented Apr. 6,1954 UNITED STATLEFE PATENT OFFICE LIFTING TOOL Application October 30,1950, Serial No. 192,896

4 Claims. 1 This invention relates to lifting tools and moreparticularly to lifting tools for handling heavy forming dies.

Forming dies, as used in the manufacture of aircraft parts for example,are often made from relatively low melting point metals, as comparedwith iron or steel. These dies eventually become obsolete and are melteddown so that the metal can be re-used. The operations necessary for thisprocess are usually performed in a foundry room where melting pots areprovided for the melting operations.

Forming die blocks, some of which exceed 20,000 pounds in weight, areordinarily handled by overhead crane hoists and are usually attached tothe chain sling and hook of the crane hoist by means of two attachmentbolts projecting through a shackle fitting for example, and screwed intoone of the numerous flanged anchor nuts which are embedded in andadjacent one surface of the die block. These flanged anchor nutsgenerally are of a standard size irrespective of the size of the dieblock and are usually dispersed around one surface thereof to receivethe standard sized bolts which support the forming die blocks in directtension when installed in stamping machines, such as drop hammers.

The operation of melting includes the step of hoisting the forming dieto a point above a melting pot, suspending the die block over andpartially into the melting pot and gradually lowering the die thereintountil the die has been entirely melted. A number of conventional liftingdevices are in current use and create a common problem, i. e., bendingof the attachment bolts with the consequent high cost of replacement.

Inasmuch as many die blocks are of lengths greater than the diameter ofthe melting pots, conventional lifting fittings are attached toattachment bolts screwed into the embedded anchor nuts, usually at twopoints at one end of a die block, and, when lifted by a hoist underthese conditions, the die block is suspended at a substantially acuteangle therefrom. When heavy blocks are lifted in this manner thestresses exerted upon the shank of the attachment bolts may drasticallybend the shank thereof and render the bolts unfit for further service.Under certain circumstances the lifting stresses could cause completestructural failure of the bolts, possibly dropping the die block into apot of molten metal, spattering the metal in all directions withprobable injury to workmen thereabout.

It is, therefore, one of the objects of this invention to provide a safeand economical means for handling heavy die blocks and the like. Otherobjects will become apparent as this specification continues.

One form this invention may take is that of a lever plate having a borebetween the ends thereof; this bore being of sufiicient diameter toreceive and preferably provide a loose fit with an attachment bolt ofthe standard size, screwing into the embedded anchor nuts of die blocks.The lever plate has an upright end at right angles to and adjacent oneend of the lever plate adjacent the bore, this upright end having acentral elongated aperture to receive a lifting hook. A number ofhardened metal spurs are provided on the underside of the other end ofthe lever plate for the purpose of digging into the die block surfaceupon contact therewith. Means are provided for laterally andlongitudinally stiffening the lever plate.

In use, the lever plate is positioned on a surface of a die block withthe hardened metal spurs above the attachment bolt which passes throughthe lever plate bore. This attachment bolt is screwed into an embeddedanchor nut adjacent the surface of the die block. The lifting hook, orthe like, is engaged in the central aperture of the upright end,adjacent and below the attachment bolt. The fulcruming of the leverplate on the hardened metal spurs causes the lifting stress to beapplied to the attachment bolt substantially entirely in tension.

The present invention will be more clearly understood by reference tothe accompanying drawings wherein:

Figure 1 shows a perspective view of a known method of handling lead topforming dies.

Figure 2 shows a perspective view of one preferred embodiment of thepresent invention.

Figure 3 is a view, partly in section and partly in elevation,illustrating the application of the device in Figure 2 to a die block.

In Figure 1 a lead top forming die block I is shown as angularlysuspended above and into a melting not 2 by means of a chain sling 3 andlifting hooks 4 of an overhead chain hoist (not shown). Each liftinghook I is engaged with the eye of an eye bolt 5. Each eye bolt 5 isscrewed into one of the customary embedded anchor nuts I (see Figure 3),cast into the die block I and adjacent one surface thereof. The dieblock I is usually rectangular in form as shown, and is suspended at asubstantially acute angle due to the end position of the eye bolts 5.This position is necessary in order to be able to feed all of the dieblock I into the melting pot 2 by degrees, gradually lowering the dieblock I until the complete melting is achieved. Under these conditionsthe full weight of the die block I exerts a shearing stress against theshank 5 of the eye bolts 5 and bending of the shank E of these bolts 5is a common occurrence. Costs of handling heavy die blocks by the oldmethods are unnecessarily high due to the necessity of frequentreplacement of the eye bolts. Furthermore the danger of complete failureof the eye bolts is ever present.

One embodiment of the present invention is shown in Figure 2. Here, alever plate 8 of substantially rectangular form has a bore 9intermediate the ends thereof of sufficient diameter to provide a loosefit with a standard type hexagon head attachment bolt I sized to screwinto the standard flanged anchor nuts I (see Figure 3) embedded in thedie blocks. Bore 9 is preferably located adjacent one end of the leverplate. This end will be the lower end in use. An upright end plate IIabuts and stands at substantially right angles below bore 9, and iswelded to the top surface of the lever plate 8 adjacent the bore 9.

An elongated aperture I2 is centrally located in the end plate II and isof sufficient size to easily receive the crane hoist lifting hook 4.Substantially rectangular side plates I3 abut each side of the leverplate 8 and the end plate II, and are welded into place for longitudinalstiffening and strengthening of the tool. An upright partition plate I4bridges the side plates I3 on the other side of bore 9 from end plate IIand is welded into place for lateral support and strengthening. Asection I5 is removed from the top edge of the partition plate I4 toallow easy engagement and disengagement of the crane hoist hook 4.

Hardened metal spurs I5, of tungsten carbide for example, are welded toopposite corners of the underside of the lever plate 8 adjacent theupper end thereof. These spurs I6 dig into the soft lead surface of thedie block I as the lever plate 8 is brought into close contact therewithand fastened down by screwing the attachment bolt II) to the flangeanchor nut I through bore 9, as shown in Figure 3. The spurs I6 preventthe lifting tool from sliding upwardly or rotating around the attachmentbolts Ill during handling operations. The penetration of the spurs I6into the surface of the die block I is increased by the lifting force.

It should be noted that in the tool of the present invention theprinciples of leverage are applied in the following manner: X is thepower or lifting point, Y is the point at which the weight is suspended,and Z is the point of fulcrum. The attachment bolts ID are therebyplaced in direct tension as demonstrated by are T and radius line r asshown in Figure 3.

Inasmuch as the lifting of heavy weights by projecting bolts is commonin industry as a whole, the present invention can be made in many formsto suit specific problems.

From the above description it will be apparent that there is thusprovided a device of the character described possessing the particularfeatures of advantage before enumerated as desirable, but whichobviously is susceptible of modification in its form, proportions,detail construction and arrangement of parts without departing from theprinciple involved or sacrificing any of its advantages.

While in order to comply with the statute, the invention has beendescribed in language more or less specific as to structural features,it is to be understood that the invention is not limited to the specificfeatures shown, but that the means and construction herein disclosedcomprise a preferred form of putting the invention into effect, and theinvention is, therefore, claimed in any of its forms or modificationswithin the legitimate and valid scope of the appended claims.

What is claimed is:

1. In combination with a block of material to be lifted, having internalanchor nuts embedded in said block adjacent an upper edge near one endof said block, a lifting assembly comprising a lever having a borebetween the ends thereof and a bolt passing through said bore andscrewed into one of said anchor nuts, said bolt extendingperpendicularly up from the top of said block and securing said lever tosaid block with one end of said lever toward the end of said block,hardened spur means on said one end of said lever in contact with said,block, said spur means being sharpened and pointed in the direction ofsaid block end to prevent slipping of said lever in up-ended positionsof said block when lifted, and means adjacent the other end of saidlever having an aperture therein for connection of a lifting hook,whereby said block can be lifted from a horizontal position to anup-ended position supported only at the attachment of said lever whilemaintaining substantially only tensile stresses in the shank of saidbolt.

2. Means for lifting a weight to be handled in various off-centerangular positions, comprising a lever member having a flat surface tocontact a face of said weight, said fiat surface having a boreperpendicularly therethrough between the ends of said lever member,hardened spur means on two corners of said flat surface at one end ofsaid lever member, said spur means protruding outwardly from said flatsurface and in a direction away from said bore, and means for engaging alifting hook at the other end of said lever member on the opposite sideof said flat surface from said spur means, and means securing said levermember tosaid weight.

3. Means for lifting a weight having a hole directed perpendicularlyinwardly from a face of said weight by a bolt positioned in said holeand engaged with said weight to prevent said bolt being pulledtherefrom, which comprises a lever member having a flat surface tocontact said face of said weight, said lever having a boreperpendicularly through said flat surface between the ends of saidlever, said bore fitting said bolt, spur means on two corners of saidflat surface at one end of said lever, said spur means protrudingoutwardly from said flat surface and in a direction away from said bore,and means for engaging a lifting hook at the other end of said lever onthe opposite side of said flat surface from said spur means.

4. In combination with a die block, a plurality of internal anchor nutsembedded therein for insertion of attachment bolts in proper locationsto tensionally support said die block in a forming machine, a liftinlever having a flat surface contacting a face of said die block, alifting bolt through said flat surface and into one of said anchor nutsnear one edge of said die block to secure said lifting lever to saidblock, spur means on the end of said lifting lever nearest said blockedge, said spur means being dug into said block to prevent slipping ofsaid lever in upended suspended positions of said block, and

means on the other end of said lever, beyond said liftin bolt, adaptedto receive a lifting hook of a hoist line, whereby said die block can belifted at one edge thereof without bending th lifting bolts.

References Cited in the file of this patent UNITED STATES PATENTS 10Number Name Date 845,724 Whidden Feb. 26, 1907 1,729,467 Whyte Sept. 24,1929

